You know that you’re getting old when a classic GCSE set text was written several years after you had finished your English Literature degree. Dennis Kelly’s “DNA” is now shaping the minds of hundreds of thousands of British schoolchildren. For those of us who did not catch “DNA” the first time around in 2007, or the second in 2012, then the King’s Players have finally delivered it to our feet at Zoo Southside.

It’s very good and also somewhat odd. Like Simon Stephens’ “Herons,” which is currently playing over at the Pleasance Zoo, “DNA” was originally intended to be performed by young teenaged actors. At first the King’s Players do not specify that they are playing children and their comic performances may lead us to assume that we are merely watching silly adults. When one of them eventually refers to what happened earlier in school, we may suppose that they are a bunch of shambolic teachers. Even once I had clocked the fact that the characters were children, I could still not really see it. They are too measured and too solemn.

The schoolboy Adam has died, mostly by accident, at the hands of his friends. His body is now lying at the bottom of a mineshaft. Those responsible turn to the taciturn genius Phil (Ben Dallyn) for help, and he accordingly engineers an elaborate miscarriage of justice in which an innocent postman is framed for Adam’s murder. “DNA” is thereafter predominantly a farce and the well-to-do accents of these kids turn them into helpless twits, rather than the sort who get embroiled in real-life gangland killings.

If you heave aside the cumbersome oddity of this play, then the acting and direction are actually superb. At first Lea (Elise Van Lil) and Phil look like Wallace and Gromit, with the former chattering witlessly away and the latter keeping his own gloomy counsel. Yet they are gradually unveiled as adversaries in their own cosmic power struggle. Lea wants to believe in human aspiration; Phil remains cynically engrossed in the succession of food items which he produces from his rucksack and polishes off in the manner of the Very Hungry Caterpillar. Most of this play fades into background noise, the gang politics becomes as trivial as any other politics, but will Phil give us a little smile? Just a little one?